Sealing wax



United States Patent Office 3,414,421 Patented Dec. 3, 1968 3,414,421SEALING WAX Merritt A. Robinson, San Anselmo, Calif., assignor to HaroldB. Sherfy, San Francisco, Calif.

N Drawing. Continuation-impart of application Ser. No. 498,115, Oct. 19,1965. This application Feb. 21, 1967, Ser. No. 617,454

2 Claims. (Cl. 106173) ABSTRACT OF THE DISCLOSURE Sealing wax isprovided in which shellac (ordinarily present in sealing wax) isreplaced in whole or in part with a cellulose plastic material such asethyl cellulose. The wax contains substantial quantities of wood rosin,hydrocarbon wax and a filler. A small amount of blending agent isincluded if the cmoponents are not miscible. A pigment and a scent maybe added in a small amount.

This application is a continuation-in-part of my copending applicationSer. No. 498,115, filed Oct. 19, 1965, entitled Sealing Wax, and nowabandoned.

This invention relates to novel compositions of matter which areparticularly useful as sealing wax.

Heretofore, sealing wax used for sealing envelops and for other likepurposes have been prepared from a formula consisting of shellac, resinand waxes, with or without added coloring material, filler and odorant.

Recently machinery has been provided to produce sealing wax and to moldit on an eflicient basis. In the use of such machinery, it is necessaryto hold substantial quantities of the molten fonmula at an elevatedtemperature for a considerable period of time. In general in theproduction of sealing wax, and more particularly when it is produced inequipment of the type just described, difficulty is encountered due tothe instability of shellac, which polymerizes in a short time at a hightemperature, such as a pouring temperature of about 300 F. This resultsin degradation of the product. Also, sealing wax as previouslyformulated tends to burn with a smoky flame and to drip burningmaterial.

:It is an object of the present invention to provide improvements in theart of sealing wax.

It is a particular object of this invention to provide a novelcomposition for use as a high quality sealing wax, which is more heatstable than previous high quality sealing wax compositions and whichdoes not become degraded when held at a convenient pouring temperaturefor a substantial period of time.

Another object of the invention is to provide a sealing wax compositionwhich does not burn with a smoky flame and which does not drip burningmaterial, to the extent that sealing wax heretofore has exhibited thesedrawbacks.

The above and other objects of the invention will be apparent from theensuing description and the appended claims.

In accordance with the present invention, the shellac component ofsealing wax is replaced in Whole or in part with a cellulose plasticmaterial typified by ethyl cellulose. A suitable formulation is asfollows, parts being percentages by weight.

Referring to the formula above, the cellulose plastic may be any of thecommon alkyl substituted celluloses such as ethyl cellulose, methylcellulose and ethyl-methyl cellulose; it may also be nitro cellulose orethyl hydroxy ethyl cellulose. In general, any modified cellulose may beused wherein ether and/or ester forming groups are incorporated in thecellulose molecule to form ether and/or ester groups and to convert thecellulose to a themoplastic material which can be melted to a fluid,preferably having a viscosity not greater than about 50,000 cps. at atemperature of about 300 F. and which is stable in the molten conditionfor a suflicient period of time to permit holding and pouring and whichwill burn without an excessively smoky flame. Ethyl cellulose of thetype N and of viscosity grade designation of 7 cps. is an excellentmaterial for this purpose. The G, K and T types may also be used.

The cellulose plastic component of the sealing wax of the presentinvention is advantageous because it is much more stable and does notpolymerize excessively, if at all, at conventional pouring temperatures;it burns without a smoky flame or with a much less smoky flame thanshellac; it burns without objectionable odor; and it has high strengthcharacteristics in that it does not fragment easily on impact.

It will be understood with regard to the cellulose plastic component andwith regard to other components of the sealing wax compositions of thepresent invention, that in any given case, for reasons of economy orotherwise, the full advantages of the invention may not be required inall cases. Thus, a material may be selected which provides less than allof the potential advantages, or which provides some one or more of theadvantages in a lesser degree than the best material available.

In the Sealing wax of the present invention, wood rosin may be used withor without hydrocarbon wax or vice versa but it is preferred to employ ablend of wood rosin and hydrocarbon wax because the hydrocarbon waximparts good burning quality, for example, it burns without a smokyflame. Wood rosin imparts good melting properties and imparts a goodgloss to the finished product. By good melting properties is meant theproperty of gradual transition between the solid and liquid states suchthat, during cooling, clean signet impressions can be formed on sealsproduced from the material.

In general any wood rosin (crude or refined, unmodified or modified bypolyermization or otherwise) may be used provided it will meltadequately and does not have too dark a color, e.g., has a color notdarker than about G on the standard scale of the US. Department ofAgriculture.

With regard to the hydrocarbon wax, any of the petroleum waxes orparaffin waxes may be used, preferably those having melting pointsbetween about and 180 F., preferably about and F. Also, a synthetichydrocarbon wax may be used instead of or in conjunction with 'apetroleum wax, for example, waxy polyethylene, polypropylene and thelike.

The wood rosin of the present invention may be any wood rosin butpreferably it is a refined rosin such as Hercules Polypale (a trademarkof Hercules Powder Co.), which is a light colored polymerized woodrosin.

The function of the blending agent is to render compatible thosecomponents which are otherwise incompatible or immiscible (orinsutficiently miscible) with one another. Thus, ethyl cellulose isinsoluble or sparingly soluble in parafiln wax and requires a blendingagent. Ethyl hydroxy ethyl cellulose is adequately soluble in wax, hencedoes not require a blending agent.

Suitable blending agents are stearic acid, other higher fatty acids,castor oil and other fatty oils and synthetic plasticizers and blendinagents such as dibutylphthalate,

di-octylphthalate, etc. Other suitable blending agents will be foundamong the plasticizers set forth in Table XIV on pages 29 and 30 of aHercules Powder Co. publication entitled Hercules Ethyl CelluloseProperties and Uses, copyright 1962.

Any suitable filler may be used, e.g., calcium carbonate in its variousforms such as ground limestone, also ground dolomite, diatomaceous earthand many others. The function of the filler'is, as the name indicates,to supplement and extend more expensive components and also to give adesirable hardness to the finished product. A filler such as calciumcarbonate which has low absorption for the organic ingredients, ispreferred because it alters viscosity of the molten product to a lesserdegree.

Any of a large variety of heat stable pigments or other coloringmaterials and odorants may be added, usually in very small quantity, toachieve whatever color and/ or odor is desired.

The following specific example will further illustrate the practice andadvantages of the present invention.

EXAMPLE 1 Stearic acid 2 /2 Finely ground calcium carbonate 25 Pigmentas desired.

Scent /2 The paraffin wax, polyethylene, stearic acid and calciumcarbonate were added to a clean pot and heat was applied to melt themixture. When this charge was nearly melted a mixer was started at slowspeed. The wood rosin was added immediately while mixing and theapplication of heat continued. When the wood rosin was fully melted anddispersed, one-half of the ethyl cellulose was added and mixing wascontinued until the mass had a smooth, creamy texture. Then theremainder of the ethyl cellulose was added and the speed of mixing wasincreased and the mixing blade was raised enough to agitate the surfaceof the liquid and to form a vortex. The pigment was then added. Thescent was added just before molding. The material was molded into sticksand into other desired shapes.

EXAMPLE 2 The formulation in this example diifers from that in Example 1primarily in the use of a greater amount of filler and a smaller amountof ethyl cellulose. The formulation was as follows:

Pounds Ethyl cellulose N-7 12 /2 Wood rosin (as in Ex. 1) 25 Parafiinwax (as in Ex. 1) 16 /2 Polyethylene (as in Ex. 1) 4 Stearic acid 3 /2Finely ground calcium carbonate 5O Pigment and scent as desired.

Sticks of this sealing wax will melt in a common candle flame and willburn like a candle without a smoky flame, with a pleasant odor and withno objectionable soot; they will drip slowly and without forming burningdrops; they are hard and glossy with a plastic feel; and a seal formedfrom the stick is slightly brittle so that it can be broken when desiredbut it will not crumble when broken. In this formulation, thepolyethylene serves to raise the melting point of the paraffin wax,thereby avoiding excessive dripping.

The sticks may be provided with wicks so that they can be burned likecandles; or the sticks may be without wicks. The sealing wax may also bemolded into other shapes. The sealing wax may also be applied by meansof a glue spreading gun, which is a well known device in which aquantity of glue (in the case of the present invention, a quantity ofwax) is heated electrically and applied.

I claim:

1. A sealing wax composition which, at room temperature is hard,slightly brittle and capable of being broken without crumbling and whichwill melt in a common candle flame, said Wax composition consistingessentially of the following ingredients in the following approximatepercentages by weight:

Ethyl cellulose 10-25. Wood rosin 20-30. Normally solid paraffin wax15-25. Inorganic mineral filler 25-45. Blending agent Quantitysufiicient to render the ethyl cellulose and paraflin wax mutuallysoluble.

2. The sealing wax composition of claim 1 wherein the ethyl cellulose isN grade, the wood rosin is refined wood rosin, and the paraflin wax hasa melting point of ll65 F.

References Cited UNITED STATES PATENTS 2,297,709 10/1942 Kauppi 106-4912,311,609 2/1943 Kauppi 106191 2,413,011 12/1946 ,Taylor 1061912,537,983 l/ll Franklin lO6-l9l 2,933,989 4/1960 DAdrian 106--191FOREIGN PATENTS 325,014 1930 Great Britain.

OTHER REFERENCES Chemistry and Technology of Waxes, by Warth, 1956, pp.690 and 845, Reinhold Publishing Co.

Commercial Waxes, Bennett, 1956, pp. 260, 261, 371, 373, 483 and 484,Chemical Publishing Co.

Industrial Waxes, by Bennett, vol. 2, 1963, pp. 58, 59, 66, and 67,Chemical Publishing Co.

MORRIS LIEBMAN, Primary Examiner.

H. H. FLETCHER, Assistant Examiner.

